Electrical connector for a multi form-factor pluggable transceiver, and data communication system including the electrical connector

ABSTRACT

An electrical connector includes an entry slot, first and second transmitter electrical pins, and first and second receiver electrical pins. The first and second transmitter electrical pins and the first and second receiver electrical pins are provided on the entry slot. The entry slot accepts a multi form-factor pluggable transceiver which has first and second optical transmitter channels and first and second optical receiver channels. The first transmitter electrical pins are electrically connected to first transmitter electrical pads of the first optical transmitter channel. The second transmitter electrical pins are electrically connected to second transmitter electrical pads of the second optical transmitter channel. The first receiver electrical pins are electrically connected to first receiver electrical pads of the first optical receiver channel. The second receiver electrical pins are electrically connected to second receiver electrical pads of the second optical receiver channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/099,522, filed Apr. 6, 2005. The entire contents of that applicationare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrical connector for a multiform-factor pluggable transceiver, an optical module assembly includingthe electrical connector and the multi form-factor pluggabletransceiver, and a data communication system including the electricalconnector.

2. Discussion of the Background

FIG. 1 shows a conventional electrical connector for a conventionalsingle form-factor pluggable transceiver. Referring to FIG. 1, theconventional electrical connector 200 is manufactured by, for example,Tyco Electronics Corp under a part number 1367073-1. The conventionalelectrical connector 200, which is provided on a printed circuit board240, has a single entry slot 210 with twenty electrical pins which aretransmitter electrical pins and receiver electrical pins. The singleentry slot 210 accepts a single-tier integrated circuit card of a matingportion of the conventional single form-factor pluggable transceiver.

FIGS. 2-5 show a conventional single form-factor pluggable transceiverwhich is manufactured by, for example, Sumitomo Electric Industries,Ltd. under a part number SCP6812-GL. The conventional single form-factorpluggable transceiver is also called as a conventional small form-factorpluggable transceiver by persons skilled in the art. Referring to FIGS.2 and 3, the conventional small form-factor pluggable transceiver 250 isprovided with a two-channel optical fiber body 262 between an opticalfiber adapter 260 and a diode module 268. The two-channel optical fiberbody 262, which is shown by partially exposed top plan views in FIGS. 2and 3, is provided with a single optical transmitter channel Tx0 and asingle optical receiver channel Rx0 which are extending through thetwo-channel optical fiber body 262. FIG. 4 shows a front view of theoptical fiber adapter 260 which is an interface optically connectable ata front surface to a two-channel optical fiber array. The optical fiberadapter 260 is optically connected at an opposite surface to one end ofthe two-channel optical fiber body 262.

FIG. 5 shows a perspective view of a mating portion 270 of theconventional small form-factor pluggable transceiver 250. The matingportion 270 is provided with a single-tier integrated circuit card 280which is electrically connected to an opposite end of the two-channeloptical fiber body 262. The single-tier integrated circuit card 280 hastransmitter electrical pads and receiver electrical pads. A pad layoutof the single-tier integrated circuit card 280 electrically matches withpin definitions of the electrical connector 200 to electrically connectthe single optical transmitter channel Tx0 and the single opticalreceiver channel Rx0 to the printed circuit board 240.

FIG. 6 shows a conventional cage assembly in which the conventionalelectrical connector 200 and the conventional small form-factorpluggable transceiver 250 are fixed. Referring to FIG. 6, theconventional cage assembly 242 includes a lower cage 244 which is fixedon the printed circuit board 240, and an upper cage 246 which covers thelower cage 244. The conventional electrical connector 200 is fixed at aclosed end portion of the conventional cage assembly 242, andelectrically connected to the printed circuit board 240. Theconventional small form-factor pluggable transceiver 250 is inserted tothe conventional cage assembly 242 from an open end portion so that thesingle-tier integrated circuit card 280 of the mating portion 270 isfurther inserted to the single entry slot 210 of the conventionalelectrical connector 200. An actuator 248 locks the conventional smallform-factor pluggable transceiver 250 to the conventional cage assembly242.

The conventional electrical connector, the conventional smallform-factor pluggable transceiver and the conventional cage assembly areconstructed according to specifications defined, for example, in SmallForm-Factor Pluggable Transceiver MultiSource Agreement dated Sep. 14,2000.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an electricalconnector includes an entry slot, first and second transmitterelectrical pins, and first and second receiver electrical pins. Thefirst and second transmitter electrical pins and the first and secondreceiver electrical pins are provided on the entry slot. The entry slotaccepts a multi form-factor pluggable transceiver. The multi form-factorpluggable transceiver has first and second optical transmitter channelsand first and second optical receiver channels. The first transmitterelectrical pins are electrically connected to first transmitterelectrical pads of the first optical transmitter channel. The secondtransmitter electrical pins are electrically connected to secondtransmitter electrical pads of the second optical transmitter channel.The first receiver electrical pins are electrically connected to firstreceiver electrical pads of the first optical receiver channel. Thesecond receiver electrical pins are electrically connected to secondreceiver electrical pads of the second optical receiver channel.

According to another aspect of the present invention, an optical moduleassembly includes a multi form-factor pluggable transceiver and anelectrical connector. The multi form-factor pluggable transceiverincludes a fiber array, a laser diode array and a photodiode array. Thefiber array has optical fibers which are divided to a transmitter groupand a receiver group. The laser diode array has laser diodes which aregrouped in a transmitter group. The photodiode array has photodiodeswhich are divided to a monitor group and a receiver group. The laserdiode array is provided between the fiber array and the photodiode arraysuch that each end surface of the optical fibers of the transmittergroup faces each laser diode of the transmitter group. Each opticalfiber of the transmitter group, each laser diode of the transmittergroup and each photodiode of the monitor group are optically aligned,respectively. Each optical fiber of the receiver group is opticallyaligned with each photodiode of the receiver group, respectively. Anelectrical connector includes an entry slot, first and secondtransmitter electrical pins, and first and second receiver electricalpins. The first and second transmitter electrical pins and the first andsecond receiver electrical pins are provided on the entry slot. Theentry slot accepts the multi form-factor pluggable transceiver. Themulti form-factor pluggable transceiver has first and second opticaltransmitter channels and first and second optical receiver channels. Thefirst transmitter electrical pins are electrically connected to firsttransmitter electrical pads of the first optical transmitter channel.The second transmitter electrical pins are electrically connected tosecond transmitter electrical pads of the second optical transmitterchannel. The first receiver electrical pins are electrically connectedto first receiver electrical pads of the first optical receiver channel.The second receiver electrical pins are electrically connected to secondreceiver electrical pads of the second optical receiver channel.

According to yet another aspect of the present invention, a datacommunication system includes an electrical connector. The electricalconnector includes an entry slot, first and second transmitterelectrical pins, and first and second receiver electrical pins. Thefirst and second transmitter electrical pins and the first and secondreceiver electrical pins are provided on the entry slot. The entry slotaccepts a multi form-factor pluggable transceiver. The multi form-factorpluggable transceiver has first and second optical transmitter channelsand first and second optical receiver channels. The first transmitterelectrical pins are electrically connected to first transmitterelectrical pads of the first optical transmitter channel. The secondtransmitter electrical pins are electrically connected to secondtransmitter electrical pads of the second optical transmitter channel.The first receiver electrical pins are electrically connected to firstreceiver electrical pads of the first optical receiver channel. Thesecond receiver electrical pins are electrically connected to secondreceiver electrical pads of the second optical receiver channel.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of an electrical connector for aconventional small form-factor pluggable transceiver of background art;

FIG. 2 is a partially exposed top plan view of the conventional smallform-factor pluggable transceiver of the background art;

FIG. 3 is a partially exposed side view of the conventional smallform-factor pluggable transceiver shown in FIG. 2;

FIG. 4 is a front view of an optical fiber adapter of the conventionalsmall form-factor pluggable transceiver shown in FIG. 2;

FIG. 5 is a perspective view of a mating portion of the conventionalsmall form-factor pluggable transceiver shown in FIG. 2;

FIG. 6 is a perspective view of a conventional cage assembly of thebackground art;

FIG. 7 is a perspective view of an electrical connector for a multiform-factor pluggable transceiver according to an embodiment of thepresent invention;

FIG. 8 is a partially exposed top plan view of the multi form-factorpluggable transceiver according to the embodiment of the presentinvention;

FIG. 9 is a partially exposed side view of the multi form-factorpluggable transceiver shown in FIG. 8;

FIG. 10 is a front view of an optical fiber adapter of the multiform-factor pluggable transceiver shown in FIG. 8;

FIG. 11 is a perspective view of a mating portion of the multiform-factor pluggable transceiver shown in FIG. 8;

FIG. 12 is a perspective view of a mating portion of a conventionalsmall form-factor pluggable transceiver with a modification according toan embodiment of the present invention;

FIG. 13 is a perspective view of an electrical connector for the multiform-factor pluggable transceiver according to an embodiment of thepresent invention;

FIG. 14 is a perspective view of an electrical connector for a multiform-factor pluggable transceiver according to an embodiment of thepresent invention;

FIG. 15 is a perspective view of a mating portion of the multiform-factor pluggable transceiver according to the embodiment of thepresent invention;

FIG. 16 is showing a data communication system according to anembodiment of the present invention;

FIG. 17 is a partially exposed top plan view of a multi form-factorpluggable transceiver according to an embodiment of the presentinvention;

FIG. 18 is a cross sectional view of the multi form-factor pluggabletransceiver cut along the line XVIII-XVIII of FIG. 17;

FIG. 19 is a cross sectional view of the multi form-factor pluggabletransceiver cut along the line XIX-XIX of FIG. 17;

FIG. 20 is a partially exposed top plan view of a multi form-factorpluggable transceiver according to an embodiment of the presentinvention;

FIG. 21 is a cross sectional view of the multi form-factor pluggabletransceiver cut along the line XXI-XXI of FIG. 20;

FIG. 22 is a front view of an optical fiber adapter of the multiform-factor pluggable transceiver in FIG. 20;

FIG. 23 is a partially exposed top plan view of a multi form-factorpluggable transceiver according to an embodiment of the presentinvention;

FIG. 24 is a cross sectional view of the multi form-factor pluggabletransceiver cut along the line XXIV-XXIV of FIG. 23;

FIG. 25 is a partially exposed top plan view of a multi form-factorpluggable transceiver according to an embodiment of the presentinvention;

FIG. 26 is a cross sectional view of the multi form-factor pluggabletransceiver cut along the line XXVI-XXVI of FIG. 25;

FIG. 27 is showing a method of manufacturing a multi form-factorpluggable transceiver according to the present invention; and

FIG. 28 is a side view of a multi form-factor pluggable transceiveraccording to an embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

The embodiments will now be described with reference to the accompanyingdrawings, wherein like reference numerals designate corresponding oridentical elements throughout the various drawings.

FIG. 7 shows an electrical connector according to an embodiment of thepresent invention. Referring to FIG. 7, the electrical connector 300 isprovided on a printed circuit board 340. The electrical connector 300 isprovided with, for example, two-tier entry slots which include a firstentry slot and a second entry slot. The first entry slot has firsttransmitter electrical pins and first receiver electrical pins. Thesecond entry slot has second transmitter electrical pins and secondreceiver electrical pins. According to this embodiment of the presentinvention, the first entry slot and the second entry slot are a lowerentry slot 310 and an upper entry slot 320, respectively.

The lower entry slot 310 has the first transmitter electrical pins andthe first receiver electrical pins which are provided on a lower wall312 and an upper wall 314. According to this embodiment of the presentinvention, the first transmitter electrical pins and the first receiverelectrical pins on the lower wall 312 are, for example, ten electricalpins 312 a-312 j. The first transmitter electrical pins and the firstreceiver electrical pins on the upper wall 314 are, for example, tenelectrical pins 314 a-314 j.

The upper entry slot 320 has the second transmitter electrical pins andthe second receiver electrical pins provided on a lower wall 322 and anupper wall 324. According to this embodiment of the present invention,the second transmitter electrical pins and the second receiverelectrical pins on the lower wall 322 are, for example, ten electricalpins 322 a-322 j. The second transmitter electrical pins and the secondreceiver electrical pins on the upper wall 324 are, for example, tenelectrical pins 324 a-324 j.

According to the embodiment of the present invention, the electricalconnector is provided with the two-tier entry slots. However, theelectrical connector may have any number of plural-tier entry slots. Inaddition, there may be one or more tiers between the lower entry slot310 and the upper entry slot 320. Further, the printed circuit board 340may be any type of circuit as long as substantially same functions areperformed.

The lower entry slot 310 is designed to accept a single-tier integratedcircuit card of a mating portion of a conventional single form-factorpluggable transceiver. The conventional single form-factor pluggabletransceiver is also called as a conventional small form-factor pluggabletransceiver by persons skilled in the art. FIGS. 2-5 show a conventionalsmall form-factor pluggable transceiver which is manufactured by, forexample, Sumitomo Electric Industries, Ltd. under a part numberSCP6812-GL. Referring to FIGS. 2 and 3, the conventional smallform-factor pluggable transceiver 250 is provided with a two-channeloptical fiber body 262 between an optical fiber adapter 260 and a diodemodule 268. The two-channel optical fiber body 262, which is shown bypartially exposed top plan views in FIGS. 2 and 3, is provided with asingle optical transmitter channel Tx0 and a single optical receiverchannel Rx0 which are extending through the two-channel optical fiberbody 262.

FIG. 4 shows a front view of the optical fiber adapter 260 which is aninterface optically connectable at a front surface to a two-channeloptical fiber array. The optical fiber adapter 260 is opticallyconnected at an opposite surface to one end of the two-channel opticalfiber body 262. FIG. 5 shows a perspective view of a mating portion 270of the conventional small form-factor pluggable transceiver 250. Themating portion 270 is provided with a single-tier integrated circuitcard 280 which is electrically connected to an opposite end of thetwo-channel optical fiber body 262.

As shown in FIG. 5, the single-tier integrated circuit card 280 of themating portion 270 is provided with transmitter electrical pads andreceiver electrical pads which are on a lower surface 282 and an uppersurface 284. The transmitter electrical pads and the receiver electricalpads on the lower surface 282 are, for example, ten electrical pads 282a-282 j. The transmitter electrical pads and the receiver electricalpads on the upper surface 284 are, for example, ten electrical pads 284a-284 j. Twenty electrical pads 282 a-282 j and 284 a-284 j of thesingle-tier integrated circuit card 280 are assigned with functions tooperate the single optical transmitter channel Tx0 and the singleoptical receiver channel Rx0 of the conventional small form-factorpluggable transceiver 250.

Referring back to FIG. 7, the lower entry slot 310 of the electricalconnector 300 is designed such that twenty electrical pins 312 a-312 jand 314 a-314 j have pin definitions to electrically match with a padlayout of the twenty electrical pads 282 a-282 j and 284 a-284 j of thesingle-tier integrated circuit card 280 of the conventional smallform-factor pluggable transceiver 250. Thus, the twenty electrical pins312 a-312 j and 314 a-314 j of the lower entry slot 310 electricallyconnect the single optical transmitter channel Tx0 and the singleoptical receiver channel Rx0 of the conventional small form-factorpluggable transceiver 250 to the printed circuit board 340.

As an alternative to the single-tier integrated circuit card 280 of theconventional small form-factor pluggable transceiver 250, the lowerentry slot 310 is also designed to accept a lower integrated circuitcard of a mating portion of a multi form-factor pluggable transceiveraccording to the embodiment of the present invention. Referring to FIGS.8 and 9, a multi form-factor pluggable transceiver 350 is provided withan optical fiber adapter 360 at one end and the mating portion 370 at anopposite end. The multi form-factor pluggable transceiver 350 has, forexample, eight optical channels which are, for example, first to fourthoptical transmitter channels Tx0-Tx3 and first to fourth opticalreceiver channels Rx0-Rx3 as shown by partially exposed top plan viewsin FIGS. 8 and 9. The eight optical channels are laid out inside aneight-channel optical fiber body 362 of the multi form-factor pluggabletransceiver 350. FIG. 10 shows a front view of the optical fiber adapter360 which is an interface to connect, for example, a multi-path push onconnector with eight optical channels to the multi form-factor pluggabletransceiver 350. FIG. 11 shows a perspective view of the mating portion370 which is provided with, for example, two-tier integrated circuitcards which are a lower integrated circuit card 380 and an upperintegrated circuit card 390. One end of each of the eight opticalchannels is optically connected to the optical fiber adapter 360. Anopposite end of each of the eight optical channels is electricallyconnected to either the lower integrated circuit card 380 or the upperintegrated circuit card 390, through a diode module 368 shown in FIGS. 8and 9. The diode module 368 is provided between the eight-channeloptical fiber body 362 and the mating portion 370, and may include, forexample, any one of or combination of a fiber array, a laser diodearray, a photodiode array and electrical circuits.

As shown in FIG. 11, the lower integrated circuit card 380 of the matingportion 370 has first transmitter electrical pads and first receiverelectrical pads which are provided on a lower surface 382 and an uppersurface 384. According to this embodiment of the present invention, thefirst transmitter electrical pads and the first receiver electrical padson the lower surface 382 are, for example, ten electrical pads 382 a-382j. The first transmitter electrical pads and the first receiverelectrical pads on the upper surface 384 are, for example, tenelectrical pads 384 a-384 j. A pad layout of twenty electrical pads 382a-382 j and 384 a-384 j of the lower integrated circuit card 380 isarranged in a substantially same manner as the pad layout of the twentyelectrical pads 282 a-282 j and 284 a-284 j of the single-tierintegrated circuit card 280 of the conventional small form-factorpluggable transceiver 250. Thus, similarly to the twenty electrical pads282 a-282 j and 284 a-284 j of the conventional small form-factorpluggable transceiver 250, the twenty electrical pads 382 a-382 j and384 a-384 j of the lower integrated circuit card 380 of the multiform-factor pluggable transceiver 350 are assigned with functions tooperate a first optical transmitter channel Tx0 and a first opticalreceiver channel Rx0 of the multi form-factor pluggable transceiver 350.

Accordingly, when the lower integrated circuit card 380 of the multiform-factor pluggable transceiver 350 is inserted to the lower entryslot 310 of the electrical connector 300, instead of the single-tierintegrated circuit card 280 of the conventional small form-factorpluggable transceiver 250, the first optical transmitter channel Tx0 andthe first optical receiver channel Rx0 of the multi form-factorpluggable transceiver 350 are electrically connected to the printedcircuit board 340. Therefore, the lower entry slot 310 of the electricalconnector 300 is compatible with both the single-tier integrated circuitcard 280 of the conventional small form-factor pluggable transceiver 250shown in FIG. 5 and the lower integrated circuit card 380 of the multiform-factor pluggable transceiver 350 shown in FIG. 11.

The upper entry slot 320 of the electrical connector 300 shown in FIG. 7is designed to accept the upper integrated circuit card 390 of themating portion 370 of the multi form-factor pluggable transceiver 350.Referring to FIG. 11, the upper integrated circuit card 390 has secondtransmitter electrical pads and second receiver electrical pads whichare provided on a lower surface 392 and an upper surface 394. Accordingto this embodiment of the present invention, the second transmitterelectrical pads and the second receiver electrical pads on the lowersurface 392 are, for example, ten electrical pads 392 a-392 j. Thesecond transmitter electrical pads and the second receiver electricalpads on the upper surface 394 are, for example, ten electrical pads 394a-394 j. Twenty electrical pads 392 a-392 j and 394 a-394 j of the upperintegrated circuit card 390 are assigned with functions to operatesecond to fourth optical transmitter channels Tx1-Tx3 and second tofourth optical receiver channels Rx1-Rx3 of the multi form-factorpluggable transceiver 350.

According to the embodiment of the present invention, electrical pins ofthe electrical connector 300 and electrical pads of the multiform-factor pluggable transceiver 350 may be electrical pads andelectrical pins, respectively, and may have any shapes or materials aslong as substantially same functions are performed. In addition,electrical pads of the two-tier integrated circuit cards of the matingportion 370 may be provided on other type or types of electricalcircuits or any other elements or materials as long as substantiallysame functions are performed.

In the multi form-factor pluggable transceiver 350 according to theembodiment of the present invention, some of functions to operate thefirst optical transmitter channel Tx0 and the first optical receiverchannel Rx0 are substantially same as those to operate the second tofourth optical transmitter channels Tx1-Tx3 and the second to fourthoptical receiver channels Rx1-Rx3. Thus, referring to FIG. 11, some ofthe twenty electrical pads 382 a-382 j and 384 a-384 j of the lowerintegrated circuit card defined with the some of the functions may beshared by the second to fourth optical transmitter channels Tx1-Tx3 andthe second to fourth optical receiver channels Rx1-Rx3. Therefore,unlike the first optical transmitter channel Tx0 and the first opticalreceiver channel Rx0, each respective pair of the second to fourthoptical transmitter channels Tx1-Tx3 and the second to fourth opticalreceiver channels Rx1-Rx3 does not require twenty electrical pads to beoperated.

Referring to FIGS. 7 and 11, the upper entry slot 320 of the electricalconnector 300 is designed such that twenty electrical pins 322 a-322 jand 324 a-324 j have pin definitions to electrically match with a padlayout of the twenty electrical pads 392 a-392 j and 394 a-394 j of theupper integrated circuit card 390 of the multi form-factor pluggabletransceiver 350. Thus, the twenty electrical pins 322 a-322 j and 324a-324 j of the upper entry slot 320 electrically connect the second tofourth optical transmitter channels Tx1-Tx3 and the second to fourthoptical receiver channels Rx1-Rx3 of the multi form-factor pluggabletransceiver 350 to the printed circuit board 340.

According to the embodiment of the present invention, the mating portion370 of the multi form-factor pluggable transceiver 350 is provided withthe two-tier integrated circuit cards as shown in FIG. 11. However, themating portion 370 may have any number of plural-tier integrated circuitcards or cards with other functions. The mating portion 370 may have oneor more tiers of cards between the lower integrated circuit card 380 andthe upper integrated circuit card 390. There may be one or more tiers ofintegrated circuit cards or cards with other functions below the lowerintegrated circuit card 380 or above the upper integrated circuit card390 as long as the lower integrated circuit card 380 and the upperintegrated circuit card 390 are positioned to be insertable to the lowerentry slot 310 and the upper entry slot 320, respectively, of theelectrical connector 300 shown in FIG. 7.

In addition, according to the embodiment of the present invention shownin FIGS. 7 and 11, the pad layout of the lower integrated circuit card380 of the multi form-factor pluggable transceiver 350 and the pindefinitions of the lower entry slot 310 of the electrical connector 300may be arranged to operate the second to fourth optical transmitterchannels Tx1-Tx3 and the second to fourth optical receiver channelsRx1-Rx3 of the multi form-factor pluggable transceiver 350. Accordingly,the pad layout of the upper integrated circuit card 390 and the pindefinitions of the upper entry slot 320 may be arranged to operate thefirst optical transmitter channel Tx0 and the first optical receiverchannel Rx0 of the multi form-factor pluggable transceiver 350.Consequently, the single-tier integrated circuit card 280 of theconventional small form-factor pluggable transceiver 250 shown in FIG. 5may be constructed to be insertable to the upper entry slot 320 of theelectrical connector 300 to operate the single optical transmitterchannel Tx0 and the single optical receiver channel Rx0 of theconventional small form-factor pluggable transceiver 250.

According to the embodiment of the present invention, the electricalconnector 300 and the multi form-factor pluggable transceiver 350 aredesigned to be fixed in a conventional cage assembly which has asubstantially same specification as a conventional cage assembly 242 forthe conventional small form-factor pluggable transceiver 250 shown inFIG. 6. As a result, without increasing a size of the conventional cageassembly for the conventional small form-factor pluggable transceiver,the electrical connector and the multiform-factor pluggable transceiveraccording to the embodiment of the present invention can increase,within limited space, a number of optical transmitter channels andoptical receiver channels.

Further, the electrical connector 300 according to the embodiment of thepresent invention is designed to be compatible with both theconventional small form-factor pluggable transceiver 250 and the multiform-factor pluggable transceiver 350. As a result, a user can chose toinstall either the conventional small form-factor pluggable transceiveror the multi form-factor pluggable transceiver, depending on necessity,even after fixing the electrical connector according to the presentinvention to the conventional cage assembly.

According to this embodiment of the present invention, when asingle-tier integrated circuit card of a mating portion of aconventional small form-factor pluggable transceiver is to be insertedto the lower entry slot 310 of the electrical connector 300 shown inFIG. 7, an upper half of an end frame of the mating portion may obstructan insertion to the lower entry slot 310. If such a case occurs, a shapeof the upper half of the end frame may be modified not to obstruct theinsertion.

FIG. 12 shows a perspective view of a mating portion of a conventionalsmall form-factor pluggable transceiver, according to an embodiment ofthe present invention, with a modification to make a single-tierintegrated circuit card of the mating portion insertable to the lowerentry slot 310 of the electrical connector 300. Referring to FIGS. 7 and12, an upper half of an end frame 276 of the mating portion 274 is cutoff thereby making the single-tier integrated circuit 286 insertable tothe lower entry slot 310. As a result, the electrical connectoraccording to this embodiment of the present invention can be compatiblewith both the conventional small form-factor pluggable transceiver withthis modification and the multi form-factor pluggable transceiver.

In addition, when the upper half of the end frame of the mating portionof the conventional small form-factor pluggable transceiver obstructsthe insertion of the single-tier integrated circuit card of theconventional small form-factor pluggable to the lower entry slot 310 ofthe electrical connector 300 shown in FIG. 7, the electrical connector300 may be modified to make the single-tier integrated circuit cardinsertable without modifying the shape of the upper half of the endframe of the mating portion.

FIG. 13 shows an electrical connector, according to an embodiment of thepresent invention, with a modification to make an upper entry slotdetachable from a lower entry slot. Referring to FIGS. 11 and 13, theelectrical connector 400 is provided with first transmitter electricalpins and first receiver electrical pins on the lower entry slot 410 andon the upper entry slot 420. The first transmitter electrical pins andthe first receiver electrical pins on the lower entry slot 410 are, forexample, twenty electrical pins. The first transmitter electrical pinsand the first receiver electrical pins on the upper entry slot 420 are,for example, twenty electrical pins. The lower entry slot 410 has pindefinitions to electrically match with a pad layout of the single-tierintegrated circuit card of the conventional small form-factor pluggabletransceiver. Because the pad layout of the lower integrated circuit card380 is arranged to be substantially same as the pad layout of thesingle-tier integrated circuit card of the conventional smallform-factor pluggable transceiver, the pin definitions of the lowerentry slot 410 also electrically match with the pad layout of the lowerintegrated circuit card 380. The upper entry slot 420 has pindefinitions to electrically match with the pad layout of the upperintegrated circuit card 390 of the multi form-factor pluggabletransceiver 350. The upper entry slot 420 is arranged to be detachablefrom the lower entry slot 410.

Accordingly, when the single-tier integrated circuit card of theconventional small form-factor pluggable transceiver is to be insertedto the lower entry slot 410 of the electrical connector 400, the upperentry slot 420 is to be detached from the lower entry slot 410 therebymaking the single-tier integrated circuit card insertable to the lowerentry slot 410. Alternatively, when the two-tier integrated circuitcards of the multi form-factor pluggable transceiver 350 is to beinserted to the lower entry slot 410 and the upper entry slot 420, theupper entry slot 420 is to be remained attached to the lower entry slot410. As a result, the electrical connector with the modificationaccording to this embodiment of the present invention can be compatiblewith both the multi form-factor pluggable transceiver and theconventional small form-factor pluggable transceiver.

Further, when the upper half of the end frame of the mating portion ofthe conventional small form-factor pluggable obstructs the insertion ofthe single-tier integrated circuit card of the conventional smallform-factor pluggable transceiver to the lower entry slot 310 of theelectrical connector 300 shown in FIG. 7, the electrical connector 300and the mating portion 370 of the multi form-factor pluggabletransceiver 350 may be modified to make the electrical connector 300compatible with the mating portion of the conventional small form-factorpluggable transceiver without modifying the mating portion of theconventional small form-factor pluggable transceiver.

FIG. 14 shows an electrical connector, according to an embodiment of thepresent invention, with a single entry slot which has transmitterelectrical pins and receiver electrical pins at substantially a half ofa pitch of electrical pins of the lower entry slot 310 of the electricalconnector 300 shown in FIG. 7. Referring to FIG. 14, the electricalconnector 500 is provided with the single entry slot 510. The singleentry slot 510 has first and second transmitter electrical pins andfirst and second receiver electrical pins. The first and secondtransmitter electrical pins and the first and second receiver electricalpins are, for example, forty electrical pins, twenty of which are on alower wall 512 and twenty of which are on an upper wall 514. The fortyelectrical pins are arranged at substantially a half of the pitch of thetwenty electrical pins of the lower entry slot 310 of the electricalconnector 300, and consequently, at substantially a half of the pitch ofthe twenty electrical pins of the single entry slot 210 of theconventional electrical connector 200. Thus, within substantially sanespace, the single entry slot 510 has two times more electrical pins thanthose of the lower entry slot 310 of the electrical connector 300 andthe single entry slot 210 of the conventional electrical connector 200.

The single entry slot 510 is designed such that the single-tierintegrated circuit card 280 of the conventional small form-factorpluggable transceiver 250 shown in FIG. 5 is insertable. The fortyelectrical pins of the single entry slot 510 are grouped in a firstgroup of electrical pins and a second group of electrical pins. Thefirst group of electrical pins includes, for example, every otherelectrical pin of the forty electrical pins which has a pin definitionwhich electrically matches with a pad definition of each correspondingone of the twenty electrical pads of the single-tier integrated circuitcard 280 of the conventional small form-factor pluggable transceiver250. Thus, the electrical connector 500 is made to be compatible withthe conventional small form-factor pluggable transceiver 250 to operatethe single optical transmitter channel Tx0 and the single opticalreceiver channel Rx0.

Further, referring to FIG. 15, a multi form-factor pluggable transceiverwith first to fourth optical transmitter channels Tx0-Tx3 and first tofourth optical receiver channels Rx0-Rx3 is provided with a matingportion 570. The mating portion 570 has a single-tier integrated circuitcard 580 provided with, for example, forty electrical pads, twenty ofwhich on a lower surface 582 and twenty of which on an upper surface584. The forty electrical pads are grouped in a first group ofelectrical pads and a second group of electrical pads.

The first group of electrical pads includes, for example, every otherelectrical pad of the forty electrical pads which is assigned with oneof functions to operate the first optical transmitter channel Tx0 andthe first optical receiver channel Rx0, positioned at a substantiallysame location as a location of each corresponding one of the twentyelectrical pads of the single-tier integrated circuit card 280 of theconventional small form-factor pluggable transceiver 250 shown in FIG.5, and assigned to have a substantially same pad definition as that ofeach corresponding pad of the single-tier integrated circuit card 280.Thus, as an alternative to the single-tier integrated circuit card 280of the conventional small form-factor pluggable transceiver 250, whenthe single-tier integrated circuit card 580 is inserted to the singleentry slot 510, the first optical transmitter channel Tx0 and the firstoptical receiver channel Rx0 of the multi form-factor pluggabletransceiver are electrically connected to a printed circuit board 540.

Furthermore, the second group of electrical pads includes, for example,another every other electrical pad of the forty electrical pads of thesingle-tier integrated circuit card 580 shown in FIG. 15 which isassigned with one of functions to operate the second to fourth opticaltransmitter channels Tx1-Tx3 and the second to fourth optical receiverchannels Rx1-Rx3. Accordingly, the single entry slot 510 shown in FIG.14 is also arranged such that the second group of electrical pinsincludes another every other electrical pin of the forty electrical pinswhich has a pin definition which electrically matches with a paddefinition of the anther every other electrical pad of the single-tierintegrated circuit card 580. Thus, when the single-tier integratedcircuit card 580 is inserted to the single entry slot 510, the second tofourth optical transmitter channel Tx1-Tx3 and the second to fourthoptical receiver channel Rx1-Rx3 of the multi form-factor pluggabletransceiver are electrically connected to the printed circuit board 540.

Therefore, the forty electrical pins of the single entry slot 510 of theelectrical connector 500 electrically connect the first to fourthoptical transmitter channels Tx0-Tx3 and the first to fourth opticalreceiver channels Rx0-Rx3 of the multi form-factor pluggable transceiverto the printed circuit board 540. Accordingly, the electrical connector500 is made to be also compatible with the multi form-factor pluggabletransceiver. As a result, the electrical connector according to thisembodiment of the present invention can be compatible with both theconventional small form-factor pluggable transceiver and the multiform-factor pluggable transceiver according to this embodiment of thepresent invention.

FIG. 16 shows a data communication system according to an embodiment ofthe present invention. Referring to FIG. 16, the data communicationsystem 600 includes at least one electrical connector 602 according toan embodiment of the present invention, which is, for example, theelectrical connector 300 shown in FIG. 7. The data communication system600 may include a multi form-factor pluggable transceiver 650 accordingto an embodiment of the present invention, which is for example, themulti form-factor pluggable transceiver 350 shown in FIGS. 8-11. Asshown in FIG. 16, the optical fiber adapter 660 of the multi form-factorpluggable transceiver 650 is connected to fiber ends 698 of acommunication fiber array 692. Another fiber ends 696 of thecommunication fiber array 692 is connected to a data communicationmodule 694.

The data communication system 600 according to the embodiment of thepresent invention may include any of other electrical connectors, forexample, shown in FIGS. 1, 13 and 14. The data communication system 600may include another embodiment of multi form-factor pluggabletransceivers one of which is, for example, the multi form-factorpluggable transceiver with the mating portion shown in FIG. 15. The datacommunication system 600 may include any one of conventional smallform-factor pluggable transceivers, one of which is, for example, theconventional small form-factor pluggable transceiver 250 shown in FIGS.2-5.

The data communication system 600 may be, for example, an intermediateoptical fiber communication system or a part of the intermediate opticalfiber communication system. A service provider of the intermediateoptical fiber communication system, which has many individualsubscribers, may be required to carry, for example, one thousand ofmulti form-factor pluggable transceivers at a node of a base station ofthe service provider. According to this embodiment of the presentinvention, because the electrical connector 602 and the multiform-factor pluggable transceiver 650 can increase, within limitedspace, a number of optical transmitter channels and optical receiverchannels, a size of the data communication system 600 can be decreased.The data communication system 600 can also be at least a part of, forexample, a satellite communication system, a telecommunication system, avisual image communication system or a computer data communicationsystem.

FIGS. 17-19 show a multi form-factor pluggable transceiver according toan embodiment of the present invention, which is, for example, the multiform-factor pluggable transceiver 350 shown in FIGS. 8-11. Referring toFIGS. 17-19, the multi form-factor pluggable transceiver 750 includes, amulti-channel, for example, 8-channel fiber array 4, a multi-channel,for example, 4-channel laser diode array 6, a laser diode submount 8, amulti-channel, for example, 8-channel photodiode array 10, and aphotodiode submount 14.

The laser diode array 6 is bonded on the laser diode submount 8. Thephotodiode array 10 is bonded to the photodiode submount 14. The fiberarray 4 and the photodiode submount 14 are connected to sandwich thelaser diode submount 8. A spacer 16 is provided between the photodiodesubmount 14 and the laser diode submount 8 to tilt the photodiode array,with a predetermined angle, away from the fiber array 4 to reduceunwanted back reflection, caused by the photodiode array 10, intooptical fibers of the fiber array. The spacer 16 has a thickness of, forexample, about 200 μm and is made of, for example, a resin material. Thephrase “about 200 μm” includes reasonable measuring margins of erroraccepted by persons skilled in the art. This use of “about” isapplicable throughout this specification.

The fiber array 4 includes eight optical fibers 4 a-4 h extendingthrough the fiber array 4. The fiber array 4 is divided to a transmittergroup which includes first to fourth optical fibers 4 a-4 d, and areceiver group which includes fifth to eighth optical fibers 4 e-4 h.The laser diode array 6 includes first to fourth laser diodes 6 a-6 dwhich are grouped together as a transmitter group. The photodiode array10 includes eight photodiodes which are divided to a monitor groupincluding first to fourth photodiodes 10 a-10 d and a receiver groupincluding fifth to eighth photodiodes 10 e-10 h.

The fiber array 4, the laser diode array 6, and the photodiode array 10are arranged such that the first to fourth optical fibers 4 a-4 d of thetransmitter group, the first to fourth laser diodes 6 a-6 d of thetransmitter group and the first to fourth photodiodes 10 a-10 d of themonitor group are optically aligned, respectively, and the fifth toeighth optical fibers 4 e-4 h of the receiver group and the fifth toeighth photodiodes 10 e-10 h of the receiver group are opticallyaligned, respectively.

The eight optical fibers 4 a-4 h are included in an eight-channeloptical fiber body 762 which corresponds to, for example, theeight-channel optical fiber body 362 in FIGS. 8 and 9. The eight-opticalfiber body 762 is optically connected to an optical fiber adapter 760 atone end, and electrically connected at an opposite end to the matingportion 770 through a diode module which includes the fiber array 4, thelaser diode array 6, the photodiode array 10, a transmitter circuit 18and a receiver circuit 20. The diode module corresponds to, for example,the diode module 368 in FIGS. 8 and 9. The first to fourth opticalfibers 4 a-4 d and the fifth to eighth optical fibers 4 e-4 h correspondto, for example, the first to fourth optical transmitter channelsTx0-Tx3 and the first to fourth optical receiver channels Rx0-Rx3 inFIGS. 8-11, respectively.

A distance between each of end surfaces of the optical fibers 4 a-4 d ofthe transmitter group and each corresponding one of the laser diodes 6a-6 d of the transmitter group is at least about 10 μm and at most about50 μm, preferably at least about 20 μm and at most about 30 μm. Adistance between each of the laser diodes 6 a-6 d of the transmittergroup and each corresponding one of the photodiodes 10 a-10 d of themonitor group is at least about 20 μm at most about 100 μm. A distancebetween each of end surfaces of the optical fibers 4 e-4 h of thereceiver group and each corresponding one of the photodiodes 10 e-10 hof the receiver group is at least about 170 μm and at most about 500 μm.

According to this embodiment of the present invention, the eight opticalfibers 4 a-4 h, the four laser diodes 6 a-6 d and the eight photodiodes10 a-10 h have substantially equal pitches which are at least about 125μm. In addition, a combined number of the optical fibers of thetransmitter group and the receiver group of the fiber array 4 is eight,which is equal to a combined number of the photodiodes of the monitorgroup and the receiver group, and twice a number of the laser diodes ofthe transmitter group. Moreover, the eight optical fibers 4 a-4 h of thefiber array are equally divided to the transmitter group and thereceiver group, and the eight photodiodes 10 a-10 h are equally dividedto the transmitter group and the receiver group.

However, the pitches between the optical fibers 4 a-4 h, the laserdiodes 6 a-6 d and the photodiodes 10 a-10 h may be arranged such that,for example, a pitch within one group of the fiber array 4 is differentfrom a pitch within another group of the fiber array 4, or a pitchbetween the transmitter group and the receiver group of the fiber array4 is different from a pitch within the transmitter group and thereceiver group of the fiber array.

Further, the fiber array 4 may have any plural number of optical fibersand may be divided to more groups than the transmitter group and thereceiver group. The photodiode array 10 may have any plural number ofphotodiodes and may be divided to more groups than the monitor group andthe receiver group. The optical fibers and the photodiodes may bedivided to plural groups unevenly, as long as each optical fiber of thetransmitter group, each corresponding laser diode of the transmittergroup and each corresponding photodiode of the monitor group can beoptically aligned, respectively, and as long as each optical fiber ofthe receiver group can be optically aligned with each correspondingphotodiode of the receiver group. A group or groups other than thetransmitter group and the receiver group of the fiber array 4 may haveone or more functions different from either or both the transmittergroup and the receiver group of the fiber array 4, and a group or groupsother than the monitor group and the receiver group of the photodiodearray 10 may have one or more functions different from either or boththe monitor group and the receiver group of the photodiode array 10.

Similarly, the laser diode array 6 may have one laser diode or anyplural number of laser diodes. The laser diode array 6 may be divided tomore groups than the transmitter group, and may be divided to pluralgroups unevenly, as long as each optical fiber of the transmitter group,each corresponding laser diode of the transmitter group and eachcorresponding photodiode of the monitor group can be optically aligned,respectively. A group or groups of the laser diode array 6 other thanthe transmitter group may have one or more functions different from thetransmitter group of the laser diode array 6.

Moreover, according to this embodiment of the present invention, thetransmitter group and the receiver group of the fiber array 4 areadjacent to each other, and the monitor group and the receiver group ofthe photodiode array 10 are adjacent to each other. In addition, thefiber array 4 and the photodiode array 10 each have a single tierincluding a first part and a second part. In the fiber array 4, theoptical fibers 4 a-4 d of the transmitter group are in the first part,and the optical fibers 4 e-4 h of the receiver group are in the secondpart. In the photodiode array 10, the photodiodes 10 a-10 d of themonitor group are in the first part, and the photodiodes 10 e-10 h ofthe receiver group are in the second part.

However, one or more optical fibers or one or more different componentsof the multi form-factor pluggable transceiver may be provided betweenthe transmitter group and the receiver group of the fiber array 4.Consequently, the photodiode array 10 may have one or more photodiodesor one or more different components of the multi form-factor pluggabletransceiver between the monitor group and the receiver group. Themonitor group and the receiver group of the photodiode array 10 may besimply spaced a part in order to be in optical alignment with the fiberarray 4. Further, the first part of the fiber array 4 and the first partof the photodiode array 10 may be either side of the second part of thefiber array 4 and the second part of the photodiode array 10, as long asthe transmitter group and the receiver group of the fiber array 4 areoptically aligned with the monitor group and the receiver group of thephotodiode array 10, respectively.

According to this embodiment of the present invention, the transmittercircuit 18 is connected to the laser diode 6 a-6 d of the transmittergroup and to the photodiodes 10 a-10 d of the monitor group. Thereceiver circuit 20 is connected to the photodiodes 10 e-110 h of thereceiver group. The transmitter circuit 18 controls the laser diodes 6a-6 d to emit optical signals according to electrical signals to betransmitted being input to the transmitter circuit 18 via signal inputlines 18 a-18 d. The photodiodes 10 a-10 d of the monitor group receiveoptical signals emitted from the laser diodes 6 a-6 d of the transmittergroup, and output received optical signals to the transmitter circuit 18to perform feed back control of the laser diodes 6 a-6 d. Thephotodiodes 10 e-10 h of the receiver group receive optical signalstransmitted via the optical fibers 4 e-4 h of the receiver group,convert received optical signals to electrical signals, and output theelectrical signals to the receiver circuit 20. The signal input lines 18a-18 d of the transmitter circuit 18 and signal output lines 20 a-20 dof the receiver circuit 20 are connected to the mating portion 770.

According to this embodiment of the present invention, the pitches ofthe optical fibers 4 a-4 h of the fiber array 4, the laser diodes 6 a-6d of the laser diode array 6 and the photodiodes 10 a-10 h of thephotodiode array 10 are substantially equal. In addition, on a singlesubstrate of the photodiode array 10, the photodiodes 10 a-10 d of themonitor group and the photodiodes 10 e-10 h of the receiver group can bepositioned together, and perform functions of both independentmonitoring of the optical output power of each of the laser diodes 6 a-6d of the transmitter group, and receiving optical signals from theoptical fibers 4 e-4 h of the receiver group.

As a result, for transmitting and receiving optical signals, the multiform-factor pluggable transceiver according to this embodiment of thepresent invention can increase, within limited space, a number ofchannels which are provided with optical output power monitors.Moreover, according to this embodiment of the present invention,structures of a multi form-factor pluggable transceiver can besimplified, and manufacturing cost of a multi form-factor pluggabletransceiver can be reduced.

FIGS. 20-22 show a multi form-factor pluggable transceiver according toan embodiment of the present invention which includes a two tieredmulti-channel fiber array and a two tiered multi-channel photodiodearray. Referring to FIGS. 20-22, the multi form-factor pluggabletransceiver 32 includes, a two tiered multi-channel, for example,16-channel fiber array 34, a multi-channel, for example, 8-channel laserdiode array 36, a laser diode submount 38, a two tiered multi-channel,for example, 16-channel photodiode array 40, and a photodiode submount44.

The two tiered fiber array 34 is provided with a first tier and a secondtier. First to eighth optical fibers 34 a-34 h in the first tier are ina transmitter group, and ninth to sixteenth optical fibers 34 i-34 p inthe second tier are in a receiver group. The laser diode array 36includes first to eighth laser diodes 36 a-36 h grouped as a transmittergroup. The two tiered photodiode array 40 is provided with a first tierand a second tier. First to eighth photodiodes 40 a-40 h in the firsttier are in a monitor group, and ninth to sixteenth photodiodes 40 i-40p in the second tier are in a receiver group.

Pitches between each optical fiber of the first tier and each opticalfiber of the second tier directly above the each optical fiber of thefirst tier, for example, between an optical fiber 34 a and an opticalfiber 34 i, between each photodiode of the first tier and eachphotodiode of the second tier directly above the each photodiode of thefirst tier, between eight optical fibers of each of the transmittergroup and the receiver group of the fiber array, between eight laserdiodes of the transmitter group of the laser diode array, and betweeneight photodiodes of each of the monitor group and the receiver group ofthe photodiode array are substantially equal, and at least about 125 μm.

The fiber array 34, the laser diode array 36 and the photodiode array 40are arranged such that the first to eighth optical fibers 34 a-34 h ofthe transmitter group, the first to eighth laser diodes 36 a-36 h of thetransmitter group and the first to eighth photodiodes 40 a-40 h of themonitor group are optically aligned, respectively, and the ninth tosixteenth optical fibers 34 i-34 p of the receiver group and the ninthto sixteenth photodiodes 40 i-40 p of the receiver group are opticallyaligned, respectively. Each of the first to eighth photodiodes 40 a-40 hof the monitor group in the first tier receives optical output power ofeach of the first to eighth laser diodes 36 a-36 h of the transmittergroup, respectively, and each of the ninth to sixteenth photodiodes 40i-40 p of the receiver group in the second tier receives optical signalsfrom each of the optical fibers 34 i-34 p of the receiver group,respectively.

According to this embodiment of the present invention, the first tierand the second tier of the fiber array are in a lower tier and an uppertier, respectively, and are adjacent to each other. The first tier andthe second tier of the photodiode array are in a lower tier and an uppertier, respectively, and are adjacent to each other. However, the firsttier may be upper in relation to the second tier in the fiber array andthe photodiode array. In addition, one or more tiers of optical fibersor photodiodes, or one or more of other components of the multiform-factor pluggable transceiver may be provided between the first tierand the second tier in either or both the fiber array and the photodiodearray. Further, the laser diode array may have one or more groups in oneor more tiers other than a tier of the transmitter group, as long aseach optical fiber of the transmitter group, each corresponding laserdiode of the transmitter group and each corresponding photodiode of themonitor group can be optically aligned, respectively, and as long aseach optical fiber of the receiver group can be optically aligned witheach corresponding photodiode of the receiver group.

Moreover, the fiber array and the photodiode array may have any pluraloptical fibers and any plural photodiodes, respectively, and may bedivided, evenly or unevenly, to plural groups in plural tiers. The laserdiode array may have one or more laser diodes, and may be grouped,evenly or unevenly, in one or more groups in one or more tiers, as longas the optical fibers of the transmitter group, the laser diodes of thetransmitter group, the photodiodes of the monitor group are opticallyaligned, respectively, and the optical fibers of the receiver group andthe photodiodes of the receiver group are optically aligned,respectively.

According to this embodiment of the present invention, the fiber arrayand the photodiode array can be arranged such that the pitches betweeneach optical fiber of the first tier and each optical fiber of thesecond tier directly above the each optical fiber of the first tier,between each photodiode of the first tier and each photodiode of thesecond tier directly above the each photodiode of the first tier,between the eight optical fibers of each of the transmitter group andthe receiver group of the fiber array, between the eight laser diodes ofthe transmitter group of the laser diode array, and between the eightphotodiodes of each of the monitor group and the receiver group of thephotodiode array are substantially equal. In addition, on a singlesubstrate of the photodiode array, the photodiodes of the monitor groupand the receiver group can be positioned adjacent to each other, andperform functions of both independent monitoring of the optical outputpower of each of the laser diodes 36 a-36 h of the transmitter group,and receiving the optical signals from the optical fibers 34 i-34 p ofthe receiver group.

As a result, the multi form-factor pluggable transceiver according tothis embodiment of the present invention can increase, within limitedspace, a number of channels which are provided with optical output powermonitors. Moreover, according to this embodiment of the presentinvention, structures of a multi form-factor pluggable transceiver canbe simplified, and manufacturing cost of a multi form-factor pluggabletransceiver can be reduced.

FIGS. 23 and 24 show a multi form-factor pluggable transceiver accordingto an embodiment of the present invention which includes a mechanicaltransfer ferrule. Referring to FIGS. 23 and 24, the multi form-factorpluggable transceiver 62 includes, a multi-channel, for example,8-channel fiber array 64, a multi-channel, for example, 4-channel laserdiode array 66, a laser diode submount 68, a multi-channel, for example,8-channel photodiode array 70, a photodiode submount 74, and themechanical transfer ferrule 80 with plural, for example, 8 opticalfibers.

The fiber array 64 and the laser diode submount 68, and the laser diodesubmount 68 and the mechanical transfer ferrule 80 are bonded to eachother to sandwich the laser diode array 66 by the fiber array 64 and themechanical transfer ferrule 80. In addition, the fiber array 64 and themechanical transfer ferrule 80 are connected by two guide pins 82 tosandwich the laser diode array 66 and the laser diode submount 68. Aspacer 76 is provided between the mechanical transfer ferrule 80 and thephotodiode submount 74 to provide space for the photodiode array 70which is bonded on the photodiode submount 74. A photodiode lead wire 88connects the photodiode array 70 to electrical circuits 90 to supplyelectrical currents and to receive electrical signals. A laser diodelead wire 86 connects the laser diode array 66 to the electricalcircuits 90 to supply electrical currents and to receive electricalsignals.

The fiber array 64 includes first to fourth optical fibers 64 a-64 d ofa transmitter group, and fifth to eighth optical fibers 64 e-64 h of areceiver group. The laser diode array 66 includes first to fourth laserdiodes 66 a-66 d of a transmitter group. The photodiode array 70includes first to fourth photodiodes 70 a-70 d of a monitor group, andfifth to eighth photodiodes 70 e-70 h of a receiver group. Themechanical transfer ferrule 80 includes first to fourth optical fibers80 a-80 d of a transmitter group and fifth to eighth optical fibers 80e-80 h of a receiver group.

The fiber array 64, the laser diode array 66, the mechanical transferferrule 80, and the photodiode array 70 are arranged such that the firstto fourth optical fibers 64 a-64 d of the transmitter group of the fiberarray, the first to fourth laser diodes 66 a-66 d of the transmittergroup, the first to fourth optical fibers 80 a-80 d of the transmittergroup of the mechanical transfer ferrule, and the first to fourthphotodiodes 70 a-70 d of the monitor group are optically aligned alongan optical axis direction of transmitter groups, respectively, and suchthat the fifth to eighth optical fibers 64 e-64 h of the receiver groupof the fiber array, the fifth to eighth optical fibers 80 e-80 h of thereceiver group of the mechanical transfer ferrule, and the fifth toeighth photodiodes 70 e-70 h of the receiver group are optically alignedalong an optical axis direction of receiver groups, respectively. Alength of the mechanical transfer ferrule 80 along each of the opticalaxis direction of transmitter groups and the optical axis direction ofreceiver groups is, for example, at least about 1 mm.

Here, each pair of the transmitter group and the receiver group of thefiber array, the monitor group and the receiver group of the photodiodearray, and the transmitter group and the receiver group of themechanical transfer ferrule are adjacent to each other within arespective pair. However, one or more groups of optical fibers or one ormore of other components of the multi form-factor pluggable transceivermay be provided between the transmitter group and the receiver group ofthe fiber array. Similarly, one or more groups of photodiodes or one ormore of other components of the multi form-factor pluggable transceivermay be provided between the monitor group and the receiver group of thephotodiode array, and one or more groups of optical fibers or one ormore of other components of the multi form-factor pluggable transceivermay be provided between the transmitter group and the receiver group ofthe mechanical ferrule, as long as the optical fibers of the transmittergroup of the fiber array, the laser diodes of the transmitter group, theoptical fibers of the transmitter group of the mechanical ferrule andthe photodiodes of the monitor group are optically aliened,respectively, and the optical fibers of the receiver group of the fiberarray, the optical fibers of the receiver group of the mechanicalferrule and the photodiodes of the receiver group are optically aligned,respectively.

According to this embodiment of the present invention, because each ofthe optical fibers of the transmitter group 80 a-80 d and the receivergroup 80 e-80 h of the mechanical transfer ferrule has a numericalaperture of at most about 0.21, the mechanical transfer ferrule 80 canreduce optical crosstalk between optical signals emitted from the laserdiodes 66 a-66 d of the transmitter group to be received by thephotodiodes 70 a-70 d of the monitor group, respectively. The mechanicaltransfer ferrule 80 can also reduce optical crosstalk between the laserdiodes 66 a-66 d of the transmitter group and the optical fibers 64 e-64h of the receiver group of the fiber array.

Moreover, because the mechanical transfer ferrule separates a pointwhere the photodiode lead wire 88 is connected to the photodiode arrayfrom a point where the laser diode lead wire 86 is connected to thelaser diode array, providing a distance of, for example, at least about1 mm, electrical crosstalk between the photodiode lead wire 88 and thelaser diode lead wire 86 can be reduced, thereby allowing the electricalcircuits 90 to accurately receive electrical signals via the photodiodelead wire 88 and the laser diode lead wire 86.

Further, because the mechanical transfer ferrule 80 and the fiber array64 are connected by the two guide pins 82, the mechanical transferferrule 80 can be precisely positioned in relation to the fiber array64, and can also increase bonding strength between the laser diodesubmount 68 and the fiber array 64. Because of the two guide pins 82,the bonding strength between the laser diode submount 68 and the fiberarray 64 can be increased to pass a temperature cycle test at −40° C.,85° C. and 500 cycles, and a high temperature and high humidity storagetest at 85° C., 85% and 5,000 hours.

As a result, the multi form-factor pluggable transceiver according tothis embodiment of the present invention can increase, within limitedspace, a number of channels which are provided with optical output powermonitors, and can also stabilize transmission and reception of opticalsignals. In addition, because use of the two guide pins increases thebonding strength between the laser diode submount and the fiber array,the multi form-factor pluggable transceiver can be used even under anenvironment with either or both a high temperature and a high humidity.Moreover, structures of a multi form-factor pluggable transceiver can besimplified, and manufacturing cost of a multi form-factor pluggabletransceiver can be reduced.

FIGS. 25 and 26 show a multi form-factor pluggable transceiver accordingto an embodiment of the present invention which includes a shield metal.Referring to FIGS. 25 and 26, the multi form-factor pluggabletransceiver 102 includes, a multi-channel, for example, 8-channel fiberarray 104, a multi-channel, for example, 4-channel laser diode array106, a laser diode submount 108, a multi-channel, for example, 8-channelphotodiode array 110, a photodiode submount 114, a mechanical transferferrule 120 with plural, for example, 8 optical fibers, and the shieldmetal 124.

The shield metal 124 is provided near a photodiode lead wire 128, bondedonto a surface of the mechanical transfer ferrule 120, and sandwiched bythe photodiode array 110 and the mechanical transfer ferrule 120. Theshield metal 124 may be between the laser diode array 106 and themechanical transfer ferrule 120. A laser diode lead wire 126 connectsthe laser diode array 106 to electrical circuits 130. The photodiodelead wire 128 connects the photodiode array 110 to the electricalcircuits 130.

According to this embodiment of the present invention, the shield metal124 prevents electrical crosstalk between the photodiode lead wire 128and the laser diode lead wire 126, which affects the photodiode leadwire 128, thereby increasing accuracy of electrical signals which theelectrical circuits 130 receive from the photodiode array 110 via thephotodiode lead wire 128. In addition, the mechanical transfer ferrule120 coated by metal or made from metal coated plastics can also preventsthe electrical crosstalk between the photodiode lead wire 128 and thelaser diode lead wire 126, thereby increasing the accuracy of theelectrical signals which the electrical circuits 130 receive from thephotodiode array 110 via the photodiode lead wire 128.

As a result, the multi form-factor pluggable transceiver according tothis embodiment of the present invention can increase, within limitedspace, a number of channels which are provided with optical output powermonitors, and can also stabilize transmission and reception of opticalsignals. In addition, because use of at least one guide pin to connectthe mechanical transfer ferrule and the fiber array increases bondingstrength between the laser diode submount and the fiber array, the multiform-factor pluggable transceiver can be used even under an environmentwith either or both a high temperature and a high humidity. Moreover,according to this embodiment of the present invention, structures of amulti form-factor pluggable transceiver can be simplified, andmanufacturing cost of a multi form-factor pluggable transceiver can bereduced.

FIG. 27 shows a method of manufacturing a multi form-factor pluggabletransceiver according to an embodiment of the present invention whichincludes a bridge and a terminal block on the bridge. Referring to FIG.27, the multi form-factor pluggable transceiver 142 includes, amulti-channel fiber array 144, a multi-channel laser diode array 146, alaser diode submount 148, a multi-channel photodiode array 150, aphotodiode submount 154, a multi-channel mechanical transfer ferrule160, the bridge 172 and the terminal block 174.

The bridge 172 connects with the laser diode submount 148. The laserdiode submount 148 has a thickness of at least about 150 μm and at mostabout 350 μm. The bridge 172 is provided with an opening so that opticalsignals transmitted from laser diodes of a transmitter group of thelaser diode array 146 and from optical fibers of a receiver group of thefiber array can pass through to be received by corresponding photodiodesof a monitor group and a receiver group of the photodiode array 150,without being attenuated. The terminal block 174, which is provided onthe bridge 172, has a bonding pad 176 to bond one end of a laser diodelead wire 166 to the terminal block 174. The mechanical transfer ferrule160 is connected with the bridge 172 and the photodiode array 150 to besandwiched by the bridge 172 and the photodiode array 150. The fiberarray 144, the laser diode array 146, the mechanical transfer ferrule160 and the photodiode array 150 are optically aligned, respectively.

According to this embodiment of the present invention, because the laserdiode submount 148 is provided with the bridge 172 and the terminalblock 174, the laser diode lead wire 166 can be bonded to the laserdiode array 146 without a need of a special tool, even when the laserdiode submount 148 is with a thickness of, for example, about 150 μm. Asa result, the multi form-factor pluggable transceiver according to thisembodiment of the present invention can reduce manufacturing cost.

In the manufacturing of the multi form-factor pluggable transceiveraccording to the present invention, in a process A, the laser diodesubmount 148, on which the laser diode array 146 is provided, ispositioned on the bridge 172, on which the terminal block 174 isprovided. Then, one end of the laser diode lead wire 166 is bonded tothe laser diode array 146 and another end of the laser diode lead wire166 to the bonding pad 176 of the terminal block 174.

In a process B, each optical fiber of a transmitter group of the fiberarray 144 is optically aligned with each corresponding laser diode ofthe transmitter group of the laser diode array 146. Then, the fiberarray 144 is bonded to the laser diode submount 148 with the laser diodearray 146, which is positioned on the bridge 172 during the process A.

In a process C, each optical fiber of a transmitter group and a receivergroup of the mechanical transfer ferrule 160 is optically aligned witheach corresponding photodiode of the monitor group and the receivergroup of the photodiode array 150. Then, the mechanical transfer ferrule160 is bonded to the photodiode submount 154 with the photodiode array150.

In a process D, the mechanical transfer ferrule 160, onto which thephotodiode submount 154 is bonded during the process C, is connectedwith the fiber array 144, onto which the laser diode submount 148 isbonded during the process B, using at least one guide pin 162, such thateach optical fiber of the transmitter group of the fiber array, eachlaser diode of the transmitter group, each optical fiber of thetransmitter group of the mechanical transfer ferrule and each photodiodeof the monitor group are optically aligned, respectively, and such thateach optical fiber of the receiver group of the fiber array, eachoptical fiber of the receiver group of the mechanical transfer ferruleand each photodiode of the receiver group are optically aligned,respectively.

According to this method of manufacturing a multi form-factor pluggabletransceiver of the present invention, because the laser diode submount148 is provided with the bridge 172 and the terminal block 174, thelaser diode lead wire 166 can be bonded to the laser diode array 146without a need of a special tool, even when the laser diode submount 148is with a thickness of, for example, about 150 μm. As a result, themulti form-factor pluggable transceiver according to this embodiment ofthe present invention can reduce manufacturing cost.

FIG. 28 shows a multi form-factor pluggable transceiver according to anembodiment of the present invention which includes a flexible cable.Referring to FIG. 28, the multi form-factor pluggable transceiver 180includes a multi-channel fiber array 184, a multi-channel laser diodearray 186, a laser diode submount 188, a multi-channel photodiode array190, a mechanical transfer ferrule 191, and the flexible cable 192.

The flexible cable 192, which replaces a photodiode submount, isprovided with a shield metal layer 194 on one side, and a tracephotodiode 196 on an opposite side to the side with the shield metallayer 194. The trace photodiode 196 has an opening through which opticalsignals, emitted by laser diodes of the laser diode array 186 and byoptical fibers of the fiber array 184, can pass to be received bycorresponding photodiodes of the photodiode array 190, without beingattenuated. The shield metal layer 194 of the flexible cable ispositioned so that electrical crosstalk between a laser diode lead wire198 and the trace photodiode 196 is prevented.

According to this embodiment of the present invention, the flexiblecable 192 includes functions of a photodiode submount, a spacer betweenthe laser diode array 186 and the photodiode array 190 or between thephotodiode array 190 and a shield metal, a shield metal between thelaser diode array 186 and the photodiode array 190, and a photodiodelead wire which connects the photodiode array 190 to electrical circuits182.

As a result, the multi form-factor pluggable transceiver according tothis embodiment of the present invention can be manufactured with fewerparts, can increase within limited space a number of channels which areprovided with optical output power monitors, and can also stabilizetransmission and reception of optical signals. In addition, because useof at least one guide pin to connect the mechanical transfer ferrule andthe fiber array increases bonding strength between the laser diodesubmount and the fiber array, the multi form-factor pluggabletransceiver can be used even under an environment with either or both ahigh temperature and a high humidity. Moreover, according to thisembodiment of the present invention, structures of a multi form-factorpluggable transceiver can be simplified, and manufacturing cost of amulti form-factor pluggable transceiver can be reduced.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

1. An electrical connector comprising: a connector body disposed on aprinted circuit board surface of a printed circuit board; at least oneentry slot configured to accept a multi form-factor pluggabletransceiver including first and second optical transmitter channels andfirst and second optical receiver channels; said at least one entry slotcomprising opposing sets of electrical pins in the connector body, theelectrical pins extending longitudinally in a direction along theprinted circuit board surface, the opposing sets of electrical pinsincluding, first and second transmitter electrical pins provided withthe at least one entry slot, the first transmitter electrical pins beingconfigured to be electrically connected to first transmitter electricalpads of the first optical transmitter channel, the second transmitterelectrical pins being configured to be electrically connected to secondtransmitter electrical pads of the second optical transmitter channel,and first and second receiver electrical pins provided with the at leastone entry slot, the first receiver electrical pins being configured tobe electrically connected to first receiver electrical pads of the firstoptical receiver channel, and the second receiver electrical pins beingconfigured to be electrically connected to second receiver electricalpads of the second optical receiver channel, wherein the at least oneentry slot comprises a single entry slot in said connector body which isprovided with the first and second transmitter electrical pins and thefirst and second receiver electrical pins.
 2. The electrical connectoraccording to claim 1, wherein the single entry slot is furtherconfigured to accept a single form-factor pluggable transceiver having asingle optical transmitter channel and a single optical receiverchannel, the first transmitter electrical pins are configured to beelectrically connected only to transmitter electrical pads of the singleoptical transmitter channel, and the first receiver electrical pins areconfigured to be electrically connected only to receiver electrical padsof the single optical receiver channel.
 3. The electrical connectoraccording to claim 1, wherein a combined number of the first transmitterelectrical pins and the first receiver electrical pins of the singleentry slot is at least twenty.
 4. The electrical connector according toclaim 2, wherein the first transmitter electrical pins and the firstreceiver electrical pins are in a first group of electrical pins, thesecond transmitter electrical pins and the second receiver electricalpins are in a second group of electrical pins, and the first group ofelectrical pins and the second group of electrical pins are alternatelypositioned in the single entry slot.
 5. The electrical connectoraccording to claim 4, wherein a separation distance between centers ofthe first group of electrical pins and the second group of electricalpins is substantially a half of a separation distance between thetransmitter and receiver electrical pads of the single form-factorpluggable transceiver.